Bottom Line:
High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour.We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour.Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms.

ABSTRACTThe combined effect of ocean acidification and warming is expected to have significant effects on several traits of marine organisms. The gastropod Concholepas concholepas is a rocky shore keystone predator characteristic of the south-eastern Pacific coast of South America and an important natural resource exploited by small-scale artisanal fishermen along the coast of Chile and Peru. In this study, we used small juveniles of C. concholepas collected from the rocky intertidal habitats of southern Chile (39 °S) to evaluate under laboratory conditions the potential consequences of projected near-future levels of ocean acidification and warming for important early ontogenetic traits. The individuals were exposed long-term (5.8 months) to contrasting pCO2 (ca. 500 and 1400 μatm) and temperature (15 and 19 °C) levels. After this period we compared body growth traits, dislodgement resistance, predator-escape response, self-righting and metabolic rates. With respect to these traits there was no evidence of a synergistic interaction between pCO2 and temperature. Shell growth was negatively affected by high pCO2 levels only at 15 °C. High pCO2 levels also had a negative effect on the predator-escape response. Conversely, dislodgement resistance and self-righting were positively affected by high pCO2 levels at both temperatures. High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour. We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour. In fact, some of the behavioural responses might be a consequence of physiological effects, such as changes in chemosensory capacity (e.g. predator-escape response) or secretion of adhesive mucous (e.g. dislodgement resistance). Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms.

pone.0151920.g004: Concholepas concholepas.Effect of two different levels of pCO2 and temperature on the metabolic rate (mean ± SE) measured in small juvenile individuals after 4.8 (a) and 5.8 (b) months of rearing in the experimental conditions. For each panel, the designations ‘temp’ and ‘pCO2’ indicate significant temperature or pCO2 (2-way ANOVA). Open and filled bars represent measurements conducted in individuals reared at current-day and high pCO2 levels respectively. In (a) the metabolic rates were measured under standard conditions of pCO2 (current-day) and temperature (15°C). However, in (b) the metabolic rates were measured at the same conditions used during rearing. Different letters above the bars indicate significant differences (p < 0.05) in Tukey's HSD post hoc test on the 2-way ANOVA analysis.

Mentions:
The results of the first series of measurements indicate a reduced metabolic rate in those individuals reared under high pCO2 conditions at both temperatures. Temperature and pCO2 level individually had a significant effect on metabolic rate (2-way ANOVA; p > 0.05; Table 6). At both rearing temperatures the metabolic rate was significantly reduced at elevated pCO2 levels. (Tukey's HSD test; p < 0.05; Fig 4a). The combination of temperature and pCO2 level had no significant effect on metabolic rate (Table 6). As expected, given the thermodynamic principles for ectothermic organisms, the second series of metabolic rates were higher at the higher temperature (Fig 4b). Only temperature had a significant effect on the metabolic rate (2-way ANOVA; p < 0.05; Table 6). The pCO2 level alone and the combination of pCO2 and temperature had not a significant effect on the metabolic rate (2-way ANOVA; p > 0.05; Table 6).

pone.0151920.g004: Concholepas concholepas.Effect of two different levels of pCO2 and temperature on the metabolic rate (mean ± SE) measured in small juvenile individuals after 4.8 (a) and 5.8 (b) months of rearing in the experimental conditions. For each panel, the designations ‘temp’ and ‘pCO2’ indicate significant temperature or pCO2 (2-way ANOVA). Open and filled bars represent measurements conducted in individuals reared at current-day and high pCO2 levels respectively. In (a) the metabolic rates were measured under standard conditions of pCO2 (current-day) and temperature (15°C). However, in (b) the metabolic rates were measured at the same conditions used during rearing. Different letters above the bars indicate significant differences (p < 0.05) in Tukey's HSD post hoc test on the 2-way ANOVA analysis.

Mentions:
The results of the first series of measurements indicate a reduced metabolic rate in those individuals reared under high pCO2 conditions at both temperatures. Temperature and pCO2 level individually had a significant effect on metabolic rate (2-way ANOVA; p > 0.05; Table 6). At both rearing temperatures the metabolic rate was significantly reduced at elevated pCO2 levels. (Tukey's HSD test; p < 0.05; Fig 4a). The combination of temperature and pCO2 level had no significant effect on metabolic rate (Table 6). As expected, given the thermodynamic principles for ectothermic organisms, the second series of metabolic rates were higher at the higher temperature (Fig 4b). Only temperature had a significant effect on the metabolic rate (2-way ANOVA; p < 0.05; Table 6). The pCO2 level alone and the combination of pCO2 and temperature had not a significant effect on the metabolic rate (2-way ANOVA; p > 0.05; Table 6).

Bottom Line:
High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour.We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour.Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms.

ABSTRACTThe combined effect of ocean acidification and warming is expected to have significant effects on several traits of marine organisms. The gastropod Concholepas concholepas is a rocky shore keystone predator characteristic of the south-eastern Pacific coast of South America and an important natural resource exploited by small-scale artisanal fishermen along the coast of Chile and Peru. In this study, we used small juveniles of C. concholepas collected from the rocky intertidal habitats of southern Chile (39 °S) to evaluate under laboratory conditions the potential consequences of projected near-future levels of ocean acidification and warming for important early ontogenetic traits. The individuals were exposed long-term (5.8 months) to contrasting pCO2 (ca. 500 and 1400 μatm) and temperature (15 and 19 °C) levels. After this period we compared body growth traits, dislodgement resistance, predator-escape response, self-righting and metabolic rates. With respect to these traits there was no evidence of a synergistic interaction between pCO2 and temperature. Shell growth was negatively affected by high pCO2 levels only at 15 °C. High pCO2 levels also had a negative effect on the predator-escape response. Conversely, dislodgement resistance and self-righting were positively affected by high pCO2 levels at both temperatures. High tenacity and fast self-righting would reduce predation risk in nature and might compensate for the negative effects of high pCO2 levels on other important defensive traits such as shell size and escape behaviour. We conclude that climate change might produce in C. concholepas positive and negative effects in physiology and behaviour. In fact, some of the behavioural responses might be a consequence of physiological effects, such as changes in chemosensory capacity (e.g. predator-escape response) or secretion of adhesive mucous (e.g. dislodgement resistance). Moreover, we conclude that positive behavioural responses may assist in the adaptation to negative physiological impacts, and that this may also be the case for other benthic organisms.